Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied bet...Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli (growth rings) observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three (1 +, 2+, 3+ ) respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1+, 2+, and 3+ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different (P 〉 0.05, P 〉 0.01).展开更多
This paper is concerned with the fossil fuel composition of carbon emissions in 10 selected Asian countries. It assesses how economic development may affect this composition through various channels. This paper contri...This paper is concerned with the fossil fuel composition of carbon emissions in 10 selected Asian countries. It assesses how economic development may affect this composition through various channels. This paper contributes to the debate on the EKC (environmental Kuznets curve) puzzle, which hypothesizes an inverted U-shaped relationship between per capita income and pollution. The paper examines the EKC hypothesis in an empirical analysis of channels that may allow for this effect. In particular, a specific subset of this general paradigm is investigated using a fractional multinomial logit model to assess how indicators associated with economic development and energy prices affect carbon emissions from coal relative to those of natural gas and oil.展开更多
Based on the Asian Corpus of English (ACE) and the British National English (BNC), I investigated the features of discourse marker (DM) so in English as lingua franca (ELF) by comparing it with its use in nati...Based on the Asian Corpus of English (ACE) and the British National English (BNC), I investigated the features of discourse marker (DM) so in English as lingua franca (ELF) by comparing it with its use in native speech. I first calculated the frequency of so in ACE and BNC. Then, taking Buysse's (2012) meta-functional theory of DM so as framework, I comprehensively analyzed the functions of so in ELF and native speech. The results show that Asian ELF speakers utter more tokens of so than native speakers, especially in the scopes of "marking results," "marking conclusion," "holding the floor," "marking summary," "opening new section of discourse," and "shift-back and elaboration." The study implies that in English teaching and learning, ELF should not be treated as an undeveloped language and that the teaching of discourse markers should focus more on the pragmatic functions than on semantic meaning in the narrow sense.展开更多
The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and ...The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.展开更多
文摘Age of African pike Hepsetus odoe from Ado Ekiti Reservoir Ekiti State, Nigeria was studied. Annuli on the opercula bones and scales were used to determine the age. The standard length of specimens examined varied between 12.50 and 29.80 cm and body weight 10-385 g. Annuli (growth rings) observed on the opercula bones of specimens with mean standard lengths 21.70 ± 1.4 cm had one real annulus, 24.80 ± 1.1 cm had two real annuli, 27.4 ± 0.9 cm had three real annuli indicating age one, two, and three (1 +, 2+, 3+ ) respectively. Growth rings observed on scales appeared as interruptions in the normal pattems of scales. Specimens with mean standard lengths of 21.3 ± 1.5 cm, 24.7 ± 0.8 cm and 27.35 ± 11 cm were interpreted to be ages 1+, 2+, and 3+ respectively. The maximum age of samples, derived from annuli on both opercula bones and scales was 3 years. Specimens below 18 cm standard length did not register any growth mark. The mean lengths at the estimated ages obtained using both opercula bones and scales were not significantly different (P 〉 0.05, P 〉 0.01).
文摘This paper is concerned with the fossil fuel composition of carbon emissions in 10 selected Asian countries. It assesses how economic development may affect this composition through various channels. This paper contributes to the debate on the EKC (environmental Kuznets curve) puzzle, which hypothesizes an inverted U-shaped relationship between per capita income and pollution. The paper examines the EKC hypothesis in an empirical analysis of channels that may allow for this effect. In particular, a specific subset of this general paradigm is investigated using a fractional multinomial logit model to assess how indicators associated with economic development and energy prices affect carbon emissions from coal relative to those of natural gas and oil.
文摘Based on the Asian Corpus of English (ACE) and the British National English (BNC), I investigated the features of discourse marker (DM) so in English as lingua franca (ELF) by comparing it with its use in native speech. I first calculated the frequency of so in ACE and BNC. Then, taking Buysse's (2012) meta-functional theory of DM so as framework, I comprehensively analyzed the functions of so in ELF and native speech. The results show that Asian ELF speakers utter more tokens of so than native speakers, especially in the scopes of "marking results," "marking conclusion," "holding the floor," "marking summary," "opening new section of discourse," and "shift-back and elaboration." The study implies that in English teaching and learning, ELF should not be treated as an undeveloped language and that the teaching of discourse markers should focus more on the pragmatic functions than on semantic meaning in the narrow sense.
基金supported by the National Natural Science Foundation of China(Grant Nos.41172163,40972116)the Chinese National Programs for Fundamental Research and Development(Grant No.2010CB950202)+1 种基金the program for New Century Excellent Talents in University(Grant No.NCET-12-0251)the Fundamental Research Funds for the Central Universities(Grant No.LZUJBKY-2013-K17)
文摘The sedimentary sequence and landscape of the Hobq desert was observed through twelve profiles along five N-S sections extending through the entire desert.Aeolian sands were found to overlie the alluvial,diluvial,and lacustrine sediments in this desert.Optically stimulated luminescence(OSL)dating results were obtained from post-IR OSL signals of quartz fractions of sand samples at the bottom of sand dunes and hills by using the Double-SAR protocol.The OSL ages reveal that the latest sand accumulation began around 19 ka in the northwestern part and 9 ka in the eastern part of the Hobq Desert.Around 7 ka,the sand accumulation was strengthened and extended southward and northward 2 ka to develop the present desert landscape.Our study suggests that the aeolian sand accumulation around 19,9 and 7 ka resulted from the weakening of the Asian summer monsoon over this region.However,the rapid development of the present Hobq desert landscape since 2 ka was likely triggered by human activities in this desert.